Your server says Running, you've copied the IP and port off the overview page, and you've pasted them into the group chat. Nobody can get in. Nothing is actually broken here: Core Keeper doesn't join by IP address, and that single fact trips up more new server owners than everything else in this guide put together.
So here's how a Core Keeper server on our platform actually works: how people get in, where the world file ends up, what you can change yourself, and what you can't.
How players actually join
Core Keeper connects players using a Game ID, a long alphanumeric string that the dedicated server generates for itself when it boots. Your players open the game, click Join Game on the main menu, paste that string in, and they're through. That really is the whole flow. No IP. No port, no port forwarding conversation, none of the usual faff.
The IP and port on your service page aren't decoration (that's what the server process binds to, and it's how we route your traffic), but no player is ever going to type them into the game.
There are two reliable places to read the Game ID:
GameID.txt, in the root of your server folder. Open File Manager in the sidebar and it's sitting next toCoreKeeperServer.exe.- The startup output in Web Console, which is the quicker route if the server is booting in front of you.
We delete GameID.txt immediately before every start. That looks alarming the first time somebody spots it, so for the record: it's deliberate, and it's precisely what Pugstorm's own Launch.PS1 script does on a self-hosted box. We didn't invent the habit, we inherited it. The server writes a fresh copy once it has finished booting. The point of it is that the ID you're reading always belongs to the run happening right now, rather than to some session from a fortnight ago.
Which brings me to the most common Core Keeper ticket we get. If GameID.txt isn't there, your server didn't start properly. It's not a broken install, and it isn't a file we forgot to ship. We've had customers reinstall twice and run a Steam update chasing a missing GameID.txt, when the real problem was the server process dying seconds into startup. Read Web Console first. Always.
One more thing, and I'd take this one seriously. The Game ID is the only thing standing between your world and a stranger, because there's no working password gate on a Core Keeper server here. The order form does ask you for a server password, but nothing in the current Core Keeper setup actually applies it, so please don't lean on it. Anyone holding that string can walk in and help themselves to your base. Keep it out of public Discords, and out of screenshots.
Where your world lives
Your world files sit in Saves\worlds\ inside the server folder. We launch with -datapath "Saves" (that's the argument doing the work), which drags the save location into the server directory where you can reach it, instead of leaving it buried in a Windows user profile the way a self-hosted install would.
A brand new server looks completely empty in there, and that's fine. The worlds folder isn't created until the world saves for the first time, which is roughly thirty seconds after the first player logs in, not at startup, which is the bit people expect. Start the server, join it once, then go and look.
Each Core Keeper service runs a single world. If you're bringing one across from a local game or another host:
- Stop the server, and wait for it to properly stop rather than assuming.
- Upload your world folder into
Saves\worlds\with File Manager. - Start the server and join, to confirm it loaded what you expected.
File Manager handles most of this happily. For anything over roughly 500 MB use SFTP on port 8822 instead (FTP is on 8821 if you'd rather) because the browser uploader gets slow and sulky with large folders. Your connection details are on the service page.
Worth saying plainly: there's no Cloud Backup or Cloud Restore in the sidebar on Core Keeper services, so nothing is quietly snapshotting your world on your behalf. Before you do anything risky (a reinstall, a build change, dropping in a world from somewhere else), download Saves\worlds\ to your own machine. It takes a minute. It's also the whole difference between an annoyance and losing the base your group spent a month on.
What the panel gives you, and what it doesn't
I'd rather you learned this from a guide than from a ticket. Core Keeper is a sparse game in our panel next to something like Palworld or Valheim (considerably sparser), and knowing that up front saves you hunting for buttons that were never there.
You get:
- Web Console, for live server output including the Game ID at startup.
- File Manager, for the world folder,
GameID.txtand the log. - Steam Update, to pull the current dedicated server build.
- Current Activity & Stats for CPU, memory and player history.
- Start, stop and restart from the service page, plus a reinstall when you want to begin again from clean.
- SFTP and FTP access.
What you don't get on a Core Keeper service is Configuration Files, Commandline Manager, Mod Manager, Cloud Backup or Cloud Restore. There are no config templates behind the first of those, so there's nothing for it to open even if you find your way to it.
The practical consequence is the bit that matters. Core Keeper takes its settings as launch arguments rather than from a config file, and the command line is locked on this game, so the things you would reasonably expect to tune yourself (world name, slot count, world seed, the Game ID) aren't editable from the panel. Open a ticket and we'll change them for you.
I'm not going to dress that up as a design decision. It's a gap, and it's a fair thing to be annoyed about.
Your server name, and getting settings changed
The name you picked when you ordered is handed to the server as -worldname, so it's the server's name and the name attached to the world all at once. It's set at provisioning, and there's no field in the panel to edit it afterwards. Don't go looking in Service Settings: it isn't hiding in there, it genuinely isn't there at all.
If you want it changed, raise a ticket. Before we touch it, take that copy of Saves\worlds\ I mentioned above. I'd want a backup in hand before anything goes near the name a world is stored under, and honestly, so should you.
Mods are a support conversation too. We don't install mods on Core Keeper servers and Mod Manager isn't enabled for the game, so if mods matter to your group, ask us what's possible before you build a whole season around them.
Restarting, updating, and one log line to ignore
When a Core Keeper patch lands, your server needs the matching build or players get bounced at the door. Run Steam Update from the sidebar, let it finish, then start the server again. Do that as soon as you notice a patch has dropped (not when somebody complains in chat) because the complaint always seems to arrive at about half eleven at night.
A restart is just stop, wait, start. Give it a moment, though. The process takes a little while to come up and write its Game ID, and hammering the start button twice tends to leave you worse off than simply waiting thirty seconds would have.
After any restart, re-read GameID.txt before assuming the old code still works. I couldn't pin down from Pugstorm's own documentation whether a dedicated server keeps its Game ID across restarts or mints a fresh one each time, and since we can't lock it to a fixed value on this setup, I'd just check. It costs five seconds and saves a confusing round of messages.
Last thing. If you go poking around in Web Console, you'll see this:
Dedicated video D3D11 device creation failed (error: 0x887a0004). This device is used specifically for video decoding, we will use software video decoding instead.
That's normal, and it isn't your problem. It's a headless Windows machine mentioning that it has no GPU for video decoding, which a game server has absolutely no use for anyway. It turns up on Core Keeper servers that are running perfectly well. If yours is genuinely misbehaving the real error is somewhere else in the log, and CoreKeeperServerLog.txt in File Manager holds the full history once Web Console has scrolled past it.
If you're stuck on any of this, or you want a setting changed that the panel won't let you near, open a ticket. We're around at all hours, and with Core Keeper in particular, a good chunk of what you might want doing is a two-minute job at our end. The Core Keeper server hosting page has the plan details, and the panel itself lives at https://control.low.ms.